Cancer is a disease characterized by uncontrolled cell division and growth within the body. In the United States, roughly a third of all women and half of all men will experience cancer in their lifetime. Polypeptides are involved in every aspect of the disease including cancer cell biology (carcinogenesis, cell cycle suppression, DNA repair and angiogenesis), treatment (immunotherapy, hormone manipulation, enzymatic inhibition), and/or diagnosis and determination of cancer type (molecular markers for breast, prostate, colon and cervical cancer for example). With the host of undesired consequences brought about by standard treatments such as chemotherapy and radiotherapy used today, genetic therapy for the manipulation of disease-related peptides and their functions provides a more targeted approach to disease diagnosis, treatment and management. However, gene therapy poses multiple challenges including undesirable immune response and safety concern due to the incorporation of the gene at random locations within the genome.
Various methods of treating cancer are under development. For example, dendritic cell (DC) vaccines have been studied as a possible anti-cancer therapy. However, DC vaccines require multiple steps of isolating DCs from a subject, ex vivo manipulation of DCs to prime the cells for tumor antigen presentation, and subsequent administration of the manipulated DCs back into the subject. Further, it is reported that the overall clinical response rates for DC vaccines remain low and the ability of DC vaccines to induce cancer regression remains low. See, e.g., Kalkinski et al., “Dendritic cell-based therapeutic cancer vaccines: what we have and what we need,” Future Oncol. 5(3):379-390 (2009).